Seismosoft | Earthquake Engineering Solutions

I am hoping to analyze a large series of Cantilevers with a vertical compression (permanent load) and a lateral force (incremental load), both at the top of the cantilever.

I am using FB inelastic elements with a single element per cantilever.

A bit surprisingly, I am getting erratic behavior using SeismoStruct 2024. The models seem to run seamlessly in SeismoStruct 2018. The element is a concrete-filled steel tube. I tweak settings and eventually get it to run occasionally. I change a single parameter, the vertical load for example, and get a message that the permanent load cannot be applied, with a "Sol_Prb" error indicated in the convergence details of the post-processor. In fact, if I eliminate the vertical, permanent load entirely, I still get the message. Even when I use element material with zero density and no permanent load, the message appears.

I have tried tweaking the loading phases, the convergence criteria, the restraints, the maximum number of iteration. I have tried subdividing the cantilever and using DB elements.

Any advice would be welcome. Love the programs - keep up the great work at SeismoSoft! - Tim

Hello Tim,

Maybe this behavior is due to the selected solver. From your description, it seems that in your model you have several cantilevers that are not connected to each other. This types of models are not supported by the more efficient Sparse/Profile solver and require the slower Skyline solver. Normally, the automatic solver option identifies the nature of the model and selects the best solver. Is it not what is happening in your model?

In any case, can you please send us the v2018 input file at support@seismosoft.com?

Thank you for your kind words and for your continuous support.
Seismosoft Support